The objectives of the proposed research are: the synthesis, determination of relative and absolute stereochemistry, and analgesic evaluation of some 4,4-disubstituted-N,N-dimethyl-1,2,3,4,-tetrahydro-2-naphthylamines as conformationally restricted analogues of methadone. Stereochemistry and conformation in the series will be established by chemical and spectroscopic procedures and by x-ray crystallographic techniques. Correlations between stereostructure and analgesic activity of the amines will be made.